If it's a Kenwood, and the antenna tuner connects with a molex connector with 2 rows of 3, try connecting a wire between the middle connection of both rows. This "fools" the radio into thinking that there is an external antenna tuner present, and when you hit the tune button, the radio puts out about 8 watts. Works great on my TS-570. Have been running it this way for several years, and this solution provides plenty of RF for my remotely mounted SGC-237.